The present invention relates to a seat frame assembly for automobiles which is adapted to be mounted on a floor of the automobile.
This kind of a seat frame assembly has been known as described in Japanese Utility Model Laid-Open Publication No. Hei 5-46351. This seat frame assembly has a first pipe disposed along a front edge and a side edge of a seat cushion pad formed in a predetermined shape and a second pipe disposed along a rear edge of the pad, and is structured such that both ends of the second pipe are respectively connected to both ends of the first pipe by welding or the like.
Further, as this kind of a seat structure for a vehicle, there has been known a seat frame structure described in a repair book for Collora Spacio issued on Jan. 13, 1997 from Toyota Jidosha Kabushiki Kaisha. This seat frame structure has a rod-shaped seat cushion frame, a pair of mutually parallel lower rails extending in a longitudinal direction and a pair of upper rails slidable with respect to the lower rails. The lower rails of the conventional seat for the vehicle are arranged in lower portions of both side edges of the seat cushion frame and fixed to a vehicle floor. Further, the upper rails are slidably supported to the lower rails and are fixed to both side edges of the seat cushion frame at both ends thereof.
Further, in this conventional seat for the vehicle, the front and rear edges of the seat cushion frame are connected by separate reinforcing members fixed to a substantially center portion in a lateral direction of the seat cushion frame, thereby securing a rigidity of the seat cushion frame.
However, in the former conventional seat frame structure, since the first and second pipes are used, a cross sectional shape is restricted to a circular shape, so that it is substantially difficult to improve a strength of the seat frame structure by means other than means involving an increase in a weight such as an increase in a thickness of plate. Further, in order to mount a reclining mechanism, a slide mechanism, a skin and the like, it is necessary to secure a mounting flat surface by changing a cross sectional shape of the seat frame structure or adding a separate bracket, so that a cost increase is caused.
Accordingly, a primary object of the invention is to provide a seat frame assembly which can improve a strength without increasing a weight.
Further, in the conventional seat for a vehicle mentioned above, since the separate reinforcing member is required for reinforcing the seat cushion frame, a number of parts is increased, so that a weight increase and a cost increase are invited in the seat for a vehicle.
Accordingly, another object of the invention is to reduce the number of parts, thereby lightening a seat for a vehicle and reducing a cost of the seat for a vehicle.
In order to achieve the primary object as mentioned above, technical conception or scope employed in the present invention is a seat frame assembly comprising a first roll formed frame having a closed rectangular cross sectional shape and wholly formed so as to extend along a front edge and both side edges of a seat cushion pad and a second roll formed frame having a closed rectangular cross sectional shape and wholly formed so as to extend along a rear edge of the pad, in which both end portions of the first roll formed frame and both end portions of the second roll formed frame are respectively connected to each other.
In accordance with this technical conception or scope, since the seat frame is constituted by the first roll formed frame and the second roll formed frame, it is possible to set a desired cross sectional shape in a comparatively free manner. Accordingly, it is possible to wholly improve a strength of the seat frame assembly or partly improve a strength of a necessary portion of the seat frame assembly owing to the cross sectional shape, so that it is possible to improve a strength of the seat frame assembly without being involved with an increase of weight.
In order to achieve another object as mentioned above, technical conception employed in the present invention is a seat for a vehicle comprising a seat cushion frame wholly formed in a frame shape, a pair of mutually parallel lower rails arranged in a substantially center portion in a lateral direction of the seat cushion frame, fixed to a vehicle floor and extending in a longitudinal direction, and a pair of mutually parallel upper rails arranged in a substantially center portion in a lateral direction of the seat cushion frame, slidably supported to the lower rails, having both ends respectively fixed to substantially center portions of front and rear edges of the seat cushion frame and extending in a longitudinal direction.
In accordance with this technical conception, since the both ends of the upper rails in the slide mechanism for supporting the seat for a vehicle to the vehicle floor in such a manner as to freely adjust in a longitudinal direction are connected to the front and rear edges of the seat cushion frame at the center portions thereof, the substantially center portions of the front and rear edges in the seat cushion frame can be connected by the upper rails. Accordingly, the upper rails can function as a reinforcing member for the seat cushion frame, so that the separate reinforcing member which is necessary in the conventional seat for a vehicle is not required. As a result, it is possible to lighten a seat for a vehicle and reduce a cost thereof.
In accordance with the present invention, since the seat frame assembly is constituted by the first roll formed frame and the second roll formed frame each having a rectangular cross section, it is possible to set a desired cross sectional shape in a comparatively free manner, so that it is possible to wholly improve a strength of the seat frame or partly improve a strength of a necessary portion of the seat frame owing to the cross sectional shape. Accordingly, it is possible to improve a strength of the seats frame without being involved with an increase of weight.
Further, in accordance with the present invention, since the first roll formed frame and the second roll formed frame are fixed to the arm member in the reclining mechanism so as to constitute a functional part of the seat frame by setting the arm member as the connection part, a number of parts can be reduced, and a weight reduction and a cost reduction can be achieved.
Still further, in accordance with the present invention, since the first roll formed frame and the second roll formed frame are fixed by setting the slide mechanism as the rail member so as to constitute a functional part of the seat frame assembly by setting the arm member as the reinforcing part, a number of parts can be reduced, and a weight reduction and a cost reduction can be achieved.
In accordance with the present invention, since the upper rail of the slide mechanism is fixed to the substantially center portion in the lateral direction of the front and rear edges of the seat cushion frame at the both ends thereof so as to connect the front and rear edges of the seat cushion frame, it is possible to cause the upper rail to function as the reinforcing part, so that a number of parts can be reduced in comparison with the conventional one, and a weight reduction of the seat for a vehicle and a cost reduction thereof can be achieved.